Propeller-dam for twin-screw vessels



(No Model.) 2 Sheets-Sheet 1.

J. HAUG. PROPELLER DAM FOR TWIN SCREW VESSELST Nb. 473,745. PatentedApr. 26,1892. "in w, I I

(No Model.) 2 Sheets-Sheet 2.

J. HAUG.

PROPELLER DAM FOR TWIN SCREW VESSELS. No. 473,745. Patented Apr. 26,1892.

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NlTED STATES PATENT OFFICE.

JOHN HAUG, OF NORRISTOIVN, PENNSYLVANIA.

PROPELLER-DAM FOR TWIN-SCREW VESSELS.

SPECIFICATION forming part of Letters Patent No. 473,745, dated April26, 1892.

Application filed January 9, 1892. Serial No. 417,441. (No model.)

To all whom it may concern.-

Be it known that I, JOHN HAUG, a citizen of the United States, and aresident of Norristown, Pennsylvania, have invented certain Improvementsin Propeller-Dams for Twin- Screw Vessels, of which the following is aspecification.

The object of my invention is to so construct a propeller-dam fortwin-screw vessels that the same can be readily moved into position toinclose the propeller and can be as readily removed after inspection orrepair has been completed, the dam being also constructed in such manneras to be applicable to either of the propellers and to be readily kepttight or free from water during the time that inspection or repair isbeing carried on.

In the accompanying drawings, Figure 1 is a transverse sectional view ofmy improved propeller-dam for twin-screw vessels, showing the sameapplied to the starboard-screw. Fig. 2 is a longitudinal section on theline 1 2, Fig. 1, and Fig. 3 is a rear elevation illustrating the mannerof applying the dam to or removing it from the propeller.

A represents a rectangular box or casing open at top and bottom andcomposed of suitable timbers secured, by preference, to framework ofwrought-iron or steel bars, andBisasemi-cylindricalboxlikewiseconstructed and hung to the bottom of thebox A at the outer side of the same by means of a suitable hinge orpivot rod (1, whereby the two parts of the dam can be permitted to swingopen, as shown in Fig. 3, so as to permit of the application of the damto or its removal from the propeller, or can be closed, as shown inFigs. I and 2, after the dam has been applied to the propeller.

Suitable semicircular openings 17 are formed in the bottoms of the foreand aft sides of the box A and in the tops of the fore and aft sides ofthe box B for the reception of the bracketbear-in g cl, which projectsfrom the hull of the vessel and carries the propeller-shaft. By

forming openings in both the fore and aft sides of the boxes A and B thedam is rendered either applicable to either the starboard or portpropeller, the openings in the forward sides of the boxes alwaysembracing the bracket-bearing and the openings in the after sides of theboxes being then closed by means of a suitable plug or stopper D, asshown in Fig. 2.

Various means may be adopted for opening and closing the lower box B ofthe dam and for retaining the same in position when closed. In thedrawings I have shown a rod f, pivoted at the lower end to the forwardside of the box B and threaded at the upper end for adaptation to a nutg, pivoted to a bearing h, mounted at the top of the box A, one of theseoperating devices being intended to be employed both atthe forward andaft sides of the dam. At the inner side of the dam I have shown a rod1', having hooked catches m for engaging with a projecting flange on theframe-work at the inner portion of the box B, as shown in Fig. 1, saidrod 1' having arms n connected by rods 19 to operating-levers s at thetop of the box A, so that the catches m can be readily operated toengage with or release the flanged frame of the box B.

By making the dam in the form of the two boxes, the lower of which isclosed except at the top and the upper closed except at the top andbottom, and by hinging the lower box to the upper one at the outer side,the dam can be applied to or removed from the propeller with thegreatest facility and can be readily kept tight or free from water whenin use, the only joint being one extending around the dam, so that thelength of the joint is less than if it extended vertically from thebottom to the top of the dam.

Although I prefer the semi-cylindrical form for the lower box B of thedam because of the minimum displacement which results when this form isadopted, it will be evident that said lower box might be triangularrectangular, or of any other available shape without departing from themain feature of my invention.

Having thus described my invention, I claim and desire to secure byLetters Patent- 1. The within-described propeller-dam for twin-screwvessels, the same consisting of upper and lower boxes hinged together attheir outer sides, whereby the inner portion of the lower box can bedropped so as to permit the dam to pass over the propeller,substantially as specified.

2. The within-described propeller-dam for twin-screw vessels, the sameconsisting of upper and lower boxes hinged together at their outersides, and each having, both in its fore and aft sides, openings forreceiving the bracket-bearing for the propeller-shaft, whereby the damis applicable to either the starboard or portpropeller, substantially asspecified.

3. The within-described propeller-dam for twin-screw vessels, the sameconsisting of an upper rectangular box and a lower semi-cylindrical box,said boxes being pivoted together at their outer sides, substantially asspecified.

4. The combination, in apropeller-damfor twin-screw vessels, of theupper and lowerboxes pivoted together at their outer sides, withoperatingscrews and nuts whereby the movement of the lower section ofthe dam in 2o respect to the upper section is controlled, substantiallyas specified.

5. The combination, in a propeller-dam for twin-screw vessels, of theupper and lower boxes pivoted together at their outer sides, withretaining-catches for locking together the inner portions of the twoboxes when the dam is closed, and with rods and levers for gperatingsaid catches, substantially as specip In testimony whereof I have signedmy name to this specification in the presence of Witnesses:

EUGENE ELTERICH, HARRY SMITH.

